Field of the Invention
The present invention relates to a processing apparatus including a plurality of communication interfaces, a processing method, and a program.
Description of the Related Art
In recent years, there has been designed a standard for using, in universal serial bus (USB) communication, a communication protocol conventionally used in a TCP/IP network. The standard is called USB Print Interface Class IPP Protocol Specification (hereinafter referred to as IPP USB Specification). By the IPP USB Specification, a hypertext transfer protocol (HTTP) used for transmitting/receiving content including HTML can be used in USB communication. In addition, an internet printing protocol (IPP), with which print data and the like are transferred between a printer and a computer, can be used in USB communication.
Specifically, it is specified in the IPP USB Specification that an IPP command request is transferred at an endpoint for bulk-out transfer of a USB print class interface, and that an IPP command response is transferred at an endpoint for bulk-in transfer thereof. The IPP is not an only protocol specified in the standard. It is specified in the standard that a command request is received and a command response is transmitted also with the HTTP in a manner similar to that of the IPP.
With the IPP USB Specification, similar communication control can be performed for basic transmission and reception of data with the HTTP without being aware of the difference in communication interfaces such as TCP/IP network or USB. A web server or a communication apparatus which has received an HTTP request from a terminal apparatus such as a PC or a tablet executes processing according to the request, and then transmits an HTTP response as a result of the processing to the terminal apparatus. In doing so, the communication between the terminal apparatus and the web server or the communication apparatus can be controlled similarly irrespective of whether using the TCP/IP network or the USB.
In Japanese Patent Application Laid-Open No. 2009-44232, prior to transmission of scanned data, an image processing apparatus transmits, to a terminal apparatus, a response including information regarding an ability of the image processing apparatus to perform split transmission of the scanned data, then splits and transmits the scanned data to the terminal apparatus.
However, in Japanese Patent Application Laid-Open No. 2009-44232, there may be a case where reading of a document cannot be started immediately, or a case where even a first split transmission of the scanned data cannot be performed even if the reading can be started. In such cases, in TCP/IP network communication and USB communication, after transferring all data of an HTTP request, the terminal apparatus as a request source stands by for a response from the image processing apparatus as a request destination. However, in a case where the image processing apparatus cannot process the HTTP request temporarily and cannot transmit a response even after a long period of time has elapsed, some terminal apparatus may determine that the image processing apparatus is in an error condition and discards the request. In addition, some terminal apparatus may stand by permanently until it is turned off, whereby processing performed by the terminal apparatuses may be occupied.